Founded in 2007, Avaaz.org has quickly become the biggest and most ambitious of a new breed of activist organisation, designed for a wired, globalised world. It has established a network of activists and civilian journalists on the ground in Syria – where it played a key role in helping to rescue the British journalist Paul Conroy from the besieged city of Homs – and across the Arab world.

Its website describes it as "the world in action" and "the campaigning community bringing people-powered politics to decision-making worldwide".

The name means "voice" in Farsi and several other Asian and European languages, and the idea is to provide a vehicle for like-minded people across the world to organise quickly over burning political issues and apply pressure on governments through online petitions or street protests.

Its founding president is Ricken Patel, a Canadian-British veteran of the International Crisis Group, a global thinktank, and MoveOn.org, a progressive American group. He runs a team of campaigners around the world, with offices in New York, Rio, Delhi, Madrid and Sydney.

Avaaz is funded by member contribution and says it does not accept money from any government or corporation. It sets its campaigning priorities by canvassing its 13-million-strong membership worldwide.

Among hundreds of global campaigns, Avaaz has taken on the Murdoch media empire in Britain, targeted the Bush administration for its resistance to action on climate change, supported anti-corruption campaigners in India, and supported pro-democracy groups in Burma and Tibet. It collected more than a million signatures for a petition focused on France, to ban pesticides suspected of killing off bees.

The network has taken on a prominent and more physically risky role in the Arab spring, providing satellite phones and other communication equipment to pro-democracy groups in Libya, Egypt and Syria.

Before this engagement, Avaaz.org had been criticised by some as "clicktivism" – implying a lazy form of protest involving little effort from its followers. Patel rejected the claim, pointing out that the online activism led to real consequences. "It's important to look beyond the technology," he told the Guardian last July.

Amid the bloodshed of Syria, the organisation's commitment is less likely to be queried. The question its critics are raising now is whether a group that started out in the high-tech safety of the internet has found itself out of its depth in a brutal conflict in the real world.